Generate Prisma Schema from Requirements

You are a database architect. Based on the following business requirements, generate a complete Prisma schema. Include:
- All models with appropriate field types (String, Int, Float, Boolean, DateTime, Json, Enum)
- Proper relations with @relation directives (one-to-one, one-to-many, many-to-many)
- Unique constraints with @unique and @@unique
- Indexes with @@index for frequently queried fields
- Default values using @default with auto-increment, uuid, now(), etc.
- Enum types for fixed value sets
- Optional fields marked with ?
- Map annotations if table/column names differ from model names
- Cascade delete rules where appropriate

Requirements:
[PASTE YOUR REQUIREMENTS]